"The pollution caused due to dust storm was expected to settle but the wind speed reduced yesterday, causing the dust that entered Delhi to get trapped in the atmosphere leading to prolonging of pollution," Beig said.

The Delhi-based think-tank Centre for Science and Environment (CSE) has estimated that the power sector alone contributes 60% of the PM (particulate matter), 45% of sulphur dioxide, 30% of nitrogen oxides and 80% of mercury emissions of the total emissions from the industrial sector.

With the Green Court stepping in for action in the continuously rising levels of pollutants in the region, the district magistrate of Gautam Budh Nagar BN Singh, today stated that the directive will be enforced from Friday morning.

NGT issued notices to the ministries of road transport and highways (MoRTH), and environment, Society of Indian Automobile Manufacturers (SIAM) and Central Pollution Control Board (CPCB) on Wednesday asking them to respond to the plea within two weeks.

This is because October, November and December, the months when air pollution goes into the “emergency” zone have gone by. Air quality analysts say there is a slim chance of “emergency” days in May, which sees another spike in pollution levels but not after that.

The Centre has empowered the Supreme Court-mandated EPCA (Environment Pollution Control Authority) to enforce the plan under which odd-even scheme and halt on construction activities may be imposed across the NCR if air quality remains at the 'emergency' level for 48-hours.

EPCA observed that switching to BS IV as early as possible will have an enormous air pollution benefit—80% reduction in particulate matter (PM) emissions. But with the firms still unprepared for this transition, the enforcement of the BS IV norm is likely to slow down.

In fact, segment leaders like Maruti Suzuki, Tata Motors and Hero MotoCorp have reported de-growth of 34.3 per cent, 45 per cent and 20 per cent, respectively giving a clear indication of a prolonged slowdown in the sector.